Solve for x
x=\frac{3\sqrt{2}}{2}+4\approx 6.121320344
x=-\frac{3\sqrt{2}}{2}+4\approx 1.878679656
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x-5+2x-3=\left(x-5\right)\left(2x-3\right)
Variable x cannot be equal to any of the values \frac{3}{2},5 since division by zero is not defined. Multiply both sides of the equation by \left(x-5\right)\left(2x-3\right), the least common multiple of 2x-3,x-5.
3x-5-3=\left(x-5\right)\left(2x-3\right)
Combine x and 2x to get 3x.
3x-8=\left(x-5\right)\left(2x-3\right)
Subtract 3 from -5 to get -8.
3x-8=2x^{2}-13x+15
Use the distributive property to multiply x-5 by 2x-3 and combine like terms.
3x-8-2x^{2}=-13x+15
Subtract 2x^{2} from both sides.
3x-8-2x^{2}+13x=15
Add 13x to both sides.
16x-8-2x^{2}=15
Combine 3x and 13x to get 16x.
16x-8-2x^{2}-15=0
Subtract 15 from both sides.
16x-23-2x^{2}=0
Subtract 15 from -8 to get -23.
-2x^{2}+16x-23=0
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
x=\frac{-16±\sqrt{16^{2}-4\left(-2\right)\left(-23\right)}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, 16 for b, and -23 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-16±\sqrt{256-4\left(-2\right)\left(-23\right)}}{2\left(-2\right)}
Square 16.
x=\frac{-16±\sqrt{256+8\left(-23\right)}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{-16±\sqrt{256-184}}{2\left(-2\right)}
Multiply 8 times -23.
x=\frac{-16±\sqrt{72}}{2\left(-2\right)}
Add 256 to -184.
x=\frac{-16±6\sqrt{2}}{2\left(-2\right)}
Take the square root of 72.
x=\frac{-16±6\sqrt{2}}{-4}
Multiply 2 times -2.
x=\frac{6\sqrt{2}-16}{-4}
Now solve the equation x=\frac{-16±6\sqrt{2}}{-4} when ± is plus. Add -16 to 6\sqrt{2}.
x=-\frac{3\sqrt{2}}{2}+4
Divide -16+6\sqrt{2} by -4.
x=\frac{-6\sqrt{2}-16}{-4}
Now solve the equation x=\frac{-16±6\sqrt{2}}{-4} when ± is minus. Subtract 6\sqrt{2} from -16.
x=\frac{3\sqrt{2}}{2}+4
Divide -16-6\sqrt{2} by -4.
x=-\frac{3\sqrt{2}}{2}+4 x=\frac{3\sqrt{2}}{2}+4
The equation is now solved.
x-5+2x-3=\left(x-5\right)\left(2x-3\right)
Variable x cannot be equal to any of the values \frac{3}{2},5 since division by zero is not defined. Multiply both sides of the equation by \left(x-5\right)\left(2x-3\right), the least common multiple of 2x-3,x-5.
3x-5-3=\left(x-5\right)\left(2x-3\right)
Combine x and 2x to get 3x.
3x-8=\left(x-5\right)\left(2x-3\right)
Subtract 3 from -5 to get -8.
3x-8=2x^{2}-13x+15
Use the distributive property to multiply x-5 by 2x-3 and combine like terms.
3x-8-2x^{2}=-13x+15
Subtract 2x^{2} from both sides.
3x-8-2x^{2}+13x=15
Add 13x to both sides.
16x-8-2x^{2}=15
Combine 3x and 13x to get 16x.
16x-2x^{2}=15+8
Add 8 to both sides.
16x-2x^{2}=23
Add 15 and 8 to get 23.
-2x^{2}+16x=23
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
\frac{-2x^{2}+16x}{-2}=\frac{23}{-2}
Divide both sides by -2.
x^{2}+\frac{16}{-2}x=\frac{23}{-2}
Dividing by -2 undoes the multiplication by -2.
x^{2}-8x=\frac{23}{-2}
Divide 16 by -2.
x^{2}-8x=-\frac{23}{2}
Divide 23 by -2.
x^{2}-8x+\left(-4\right)^{2}=-\frac{23}{2}+\left(-4\right)^{2}
Divide -8, the coefficient of the x term, by 2 to get -4. Then add the square of -4 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-8x+16=-\frac{23}{2}+16
Square -4.
x^{2}-8x+16=\frac{9}{2}
Add -\frac{23}{2} to 16.
\left(x-4\right)^{2}=\frac{9}{2}
Factor x^{2}-8x+16. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(x-4\right)^{2}}=\sqrt{\frac{9}{2}}
Take the square root of both sides of the equation.
x-4=\frac{3\sqrt{2}}{2} x-4=-\frac{3\sqrt{2}}{2}
Simplify.
x=\frac{3\sqrt{2}}{2}+4 x=-\frac{3\sqrt{2}}{2}+4
Add 4 to both sides of the equation.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}